The present invention relates to a compensating reservoir for a hydraulic brake system. The reservoir consists of an upper part provided with a fill socket and of a lower part provided with an outlet. The upper and lower parts are connected in a liquid-tight manner along a separating line. The reservoir further includes a fluid chamber which communicates with a filling and supply opening of a brake master cylinder via the reservoir outlet. The reservoir also includes an auxiliary chamber which communicates with the fluid chamber and contains a liquid level indicating float device.
A compensating reservoir, for instance, is known from prior German Published Patent Application DE-OS No. 27 20 596. The compensating reservoir disclosed therein has an auxiliary chamber which is formed by a tubular body surrounding a float with a slight play and wherein the cross-section of the outlet end exceeds the cross-section of the fluid connection of the auxiliary chamber towards the remaining compensating reservoir.
A disadvantage of such prior compensating reservoirs, is that it is necessary to arrange the float in the areal center of gravity of the fluid level for the purpose of obtaining optimum accuracy in measuring the fluid level within the reservoir. In these prior reservoirs which, due to their constructional fitting position, have a very shallow and uneven-shaped design, it is extremely difficult to achieve this positioning since the location of the areal center of gravity of the fluid level varies greatly as a consequence of different driving conditions such as during acceleration, deceleration, cornering, uphill and downhill operation.
It is thus an object of the present invention to provide a compensating reservoir of the type referred to above wherein the actual fluid level can be accurately determined by means of a float which is not necessarily arranged in the fluid level's areal center of gravity as a result of the reservoir's shape, and without having to accept considerable losses of fluid.